The continuously photocatalytic degradation of methyl orange (MO) was carried out using a photocatalytic membrane reactor (PMR). The lifetime, cause of deactivation, and regeneration of Degussa P25 titanium dioxide (TiO) were investigated. The photocatalyst was deactivated when the concentration of MO in the effluent of the PMR was stable. To characterize the lifetime of the photocatalyst, we applied g MO/g TiO. The lifetime of the photocatalyst during the photocatalytic degradation of 10 mg/L MO was 3.71 times that of 5 mg/L MO. Changing the hydraulic retention time of the PMR from 0.75 to 3 h prolonged the lifetime of the photocatalyst. Deactivation of the photocatalyst was not due to pore blocking by the reactant (MO) or intermediate products. The surface adsorption of MO and the reaction intermediates deactivated the catalyst. The spent catalysts were regenerated after washing with methanol and hydrogen peroxide (HO) and then treated with heat. HO treatment generated the highest regeneration rate, because HO is a strong oxidizing agent that oxidized the deposited species on the surface of the photocatalyst.
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http://dx.doi.org/10.2166/wst.2020.091 | DOI Listing |
Environ Res
January 2025
School of Materials and Chemistry, University of Shanghai for Science and Technology, Shanghai 200093, China. Electronic address:
The pressing necessity to mitigate climate change and decrease greenhouse gas emissions has driven the advancement of heterostructure-based photocatalysts for effective CO₂ reduction. This study introduces a novel heterojunction photocatalyst formed by integrating potassium-doped polymeric carbon nitride (KPCN) with metallic Zn₃N₂, synthesized via a microwave-assisted molten salt method. The resulting Schottky contact effectively suppresses the reverse diffusion of electrons, achieving spatial separation of photogenerated charges and prolonging their lifetime, which significantly enhances photocatalytic activity and efficiency.
View Article and Find Full Text PDFNano Lett
January 2025
Key Laboratory of Quantum Materials and Devices of Ministry of Education, School of Physics, Southeast University, Nanjing 21189, China.
CuO semiconductors are highly regarded in photocatalysis for their outstanding photogenerated carrier dynamics. However, the mechanisms underlying carrier separation and recombination in CuO remain elusive, largely due to the intricate interplay between defects and facet engineering. Herein, we elucidate the critical synergy between internal defects and facets in CuO for carrier dynamics.
View Article and Find Full Text PDFEnviron Res
December 2024
Department of Environmental Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu, 41566, Republic of Korea. Electronic address:
Peroxydisulfate (PDS) activation is a crucial process for wastewater treatment in complicated water matrices. However, it is frequently limited because of poor selectivity, sluggish kinetics, and short lifetime of radicals. Therefore, in this study, an efficient sulfur-doped CN/DyFeO (SCN/DyF) Z-scheme heterostructure catalyst was rationally developed using a simple wet-chemical strategy to photoactivate PDS, which can effectively degrade norfloxacin (NOR; 96.
View Article and Find Full Text PDFJ Comput Chem
January 2025
Department of Chemistry, University of Nevada Reno, Reno, Nevada, USA.
Hydrogen gas (H) can be produced via entirely solar-driven photocatalytic water splitting (PWS). A promising set of organic materials for facilitating PWS are the so-called inverted singlet-triplet, INVEST, materials. Inversion of the singlet (S) and triplet (T) energies reduces the population of triplet states, which are otherwise destructive under photocatalytic conditions.
View Article and Find Full Text PDFChem Catal
November 2024
Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States.
The use of visible light to drive chemical transformations has a history spanning over a century. However, the development of photo-redox catalysts to efficiently harness light energy is a more recent advancement, evolving over the past two decades. While ruthenium and iridium-based photocatalysts dominate due to their photostability, long excited-state lifetimes, and high redox potentials, concerns about sustainability and cost have shifted attention to first-row transition metals.
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